The reader may have felt some surprise at this strange jump from the _patria potestas_ to a discussion of merely zoological facts, which have nothing to do, directly, with the history of human marriage. But we have now to deal with the sexual selection of man, and, for the right understanding of this, it was necessary to show that the sexual selection of the lower animals is entirely subordinate to the great law of natural selection. Mr. Darwin discussed the origin of the secondary sexual characters as a preliminary to the statement of his theory regarding the origin of man, and of the different races of men. At the end of the next chapter we shall consider whether this theory appears to be in accordance with facts or not. CHAPTER XII THE SEXUAL SELECTION OF MAN: TYPICAL BEAUTY By the “Sexual Selection of Man” is meant the choice made by men and women as regards relations with the opposite sex. Mr. Darwin has shown that such selection takes place among the lower Vertebrata, and, judging from what we know of domesticated animals, it is much more common in the case of females than in that of males. The male, indeed, as a rule, seems to be ready to pair with any female, provided she belongs to his own species.[1516] As this probably depends upon the great strength of his sexual impulse, we may infer that in primitive times, when man had a definite pairing season, he displayed a like tendency, and that the sexual instinct, in proportion as it has become less intense, has become more discriminating.